Download or read book Post fire Vegetation and Climate Dynamics in Low elevation Forests Over the Last Three Millennia in Yellowstone National Park written by M. Allison Stegner and published by . This book was released on 2019 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conifer forests of the western US are historically well adapted to wildfires, but current warming is creating novel disturbance regimes that may fundamentally change future forest dynamics. Stand-replacing fires can catalyze forest reorganization by providing periodic opportunities for establishment of new tree cohorts that set the stage for stand development for centuries to come. Extensive research on modern and past fires in the Northern Rockies reveals how variations in climate and fire have led to large changes in forest distribution and composition. Unclear, however, is the importance of individual fire episodes in catalyzing change. We used high-resolution paleoecologic and paleoclimatic data from Crevice Lake (Yellowstone National Park, Wyoming, USA), to explore the role of fire in driving low-elevation forest dynamics over the last 2820 yr. We addressed two questions: 1) did low-elevation forests at Crevice Lake experience abrupt community-level vegetation changes in response to past fire events? 2) Did the interaction of short-term disturbance events (fire) and long-term climate change catalyze past shifts in forest composition? Over the last 2820 yr, we found no evidence for abrupt community-level vegetation transitions at Crevice Lake, and no evidence that an interaction of climate and fire produced changes in the relative abundance of dominant plant taxa. In part, this result reflects limitations of the datasets to detect past event-specific responses and their causes. Nonetheless, the relative stability of the vegetation to fires over the last 2820 yr provides a local baseline for assessing current and future ecological change. Observations of climate?fire?vegetation dynamics in recent decades suggest that this multi-millennial-scale baseline may soon be exceeded.

Download or read book Yellowstone in the Afterglow written by Mary Ann Franke and published by . This book was released on 2000 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book After the Fires written by Linda L. Wallace and published by Yale University Press. This book was released on 2004-01-01 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Americans currently choose their president through the electoral college, an extraordinarily complex mechanism that may elect a candidate who does not receive the most votes. In this provocative book, George Edwards III argues that, contrary to what supporters of the electoral college claim, there is no real justification for a system that might violate majority rule. Drawing on systematic data, Edwards finds that the electoral college does not protect the interests of small states or racial minorities, does not provide presidents with effective coalitions for governing, and does little to protect the American polity from the alleged harms of direct election of the president. In fact, the electoral college distorts the presidential campaign so that candidates ignore most small states and some large ones and pay little attention to minorities, and it encourages third parties to run presidential candidates and discourages party competition in many states. Edwards demonstrates effectively that direct election of the president without a runoff maximizes political equality and eliminates the distortions in the political system caused by the electoral college.

Download or read book Postglacial Fire Vegetation and Climate History Across an Elevational Gradient in the Northern Rocky Mountains USA and Canada written by Mitchell J. Power and published by . This book was released on 2011 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 13,100-year-long high-resolution pollen and charcoal record from Foy Lake in western Montana is compared with a network of vegetation and fire-history records from the Northern Rocky Mountains. New and previously published results were stratified by elevation into upper and lower and tree line to explore the role of Holocene climate variability on vegetation dynamics and fire regimes. During the cooler and drier Lateglacial period, ca 13,000 cal yr BP, sparsely vegetated Picea parkland occupied Foy Lake as well as other low- and high-elevations with a low incidence of fire. During the warmer early Holocene, from ca 11,000-7500 cal yr BP, low-elevation records, including Foy, indicate significant restructuring of regional vegetation as Lateglacial Picea parkland gave way to a mixed forest of Pinus-Pseudotsuga-Larix . In contrast, upper tree line sites (ca >2000 m) supported Pinus albicaulis and/or P. monticola-Abies-Picea forests in the Lateglacial and early Holocene. Regionally, biomass burning gradually increased from the Lateglacial times through the middle Holocene. However, upper tree line fire-history records suggest several climate-driven decreases in biomass burning centered at 11,500, 8500, 4000, 1600 and 500 cal yr BP. In contrast, lower tree line records generally experienced a gradual increase in biomass burning from the Lateglacial to ca 8000 cal yr BP, then reduced fire activity until a late Holocene maximum at 1800 cal yr BP, as structurally complex mesophytic forests at Foy Lake and other sites supported mixed-severity fire regimes. During the last two millennia, fire activity decreased at low elevations as modern forests developed and the climate became cooler and wetter than before. Embedded within these long-term trends are high amplitude variations in both vegetation dynamics and biomass burning. High-elevation paleoecological reconstructions tend to be more responsive to long-term changes in climate forcing related to growing-season temperature. Low-elevation records in the NRM have responded more abruptly to changes in effective precipitation during the late Holocene. Prolonged droughts, including those between 1200 and 800 cal yr BP, and climatic cooling during the last few centuries continues to influence vegetation and fire regimes at low elevation while increasing temperature has increased biomass burning in high elevations.

Download or read book Ecological Dynamics on Yellowstone s Northern Range written by National Research Council and published by National Academies Press. This book was released on 2002-02-01 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecological Dynamics on Yellowstone's Northern Range discusses the complex management challenges in Yellowstone National Park. Controversy over the National Park Service's approach of "natural regulation" has heightened in recent years because of changes in vegetation and other ecosystem components in Yellowstone's northern range. Natural regulation minimizes human impacts, including management intervention by the National Park Service, on the park ecosystem. Many have attributed these changes to increased size of elk and other ungulate herds. This report examines the evidence that increased ungulate populations are responsible for the changes in vegetation and that the changes represent a major and serious change in the Yellowstone ecosystem. According to the authors, any human intervention to protect species such as the aspen and those that depend on them should be prudently localized rather than ecosystem-wide. An ecosystem-wide approach, such as reducing ungulate populations, could be more disruptive. The report concludes that although dramatic ecological change does not appear to be imminent, approaches to dealing with potential human-caused changes in the ecosystem, including those related to climate change, should be considered now. The need for research and public education is also compelling.

Download or read book Vegetation Response to Wildfire and Climate Forcing in a Rocky Mountain Lodgepole Pine Forest Over the Past 2 500 Years written by Barrie Victoria Chileen and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Influence of Fire Interval and Climate on Successional Patterns in Yellowstone National Park written by Tania Schoennagel and published by . This book was released on 2002 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Resilience to Changing Climate and Wildfire in Subalpine Conifer Forests of Greater Yellowstone written by Winslow D. Hansen and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate and disturbance regimes are rapidly changing in earth's forests, and these trends are expected to continue through the 21st century. It remains unresolved whether and where forests will absorb increased perturbations without changing qualitatively and where forest resilience might erode. This dissertation provides a foundation to begin addressing these uncertainties. I combined field observation, experiments, and process-based simulation to study effects of changing climate and wildfire on postfire tree regeneration and forest resilience in Yellowstone National Park, the largest intact wildland area of the contiguous United States. Chapter 1 quantifies effects of ecological filters on a colonizing cohort of aspen. These aspen trees established from seed after the 1988 fires and survived at higher elevations than their prefire distribution. I then conducted a long-term field experiment and shorter controlled-environment experiment to determine how temperature and soil moisture consistent with 21st-century projections may alter postfire seedling establishment of two widespread conifers (Chapter 2). In chapters 3 and 4, I used a forest simulation model to test multiple mechanisms of regeneration failure and to explore how suppression may alter 21st-century fire and forests. Long-term study of colonizing aspen demonstrated how wildfire can catalyze rapid shifts in tree-species distributions. Aspen seedlings were initially favored at lower elevations close to their prefire distribution. By 25yrs postfire, aspen was favored to survive at higher elevations, likely due to warming. From the experiments, it appears postfire drought may be a powerful force for change in subalpine forests because regeneration was drastically reduced under hotter-drier conditions. Simulations, where multiple climate-fire drivers could be considered over longer periods, however, indicate the potential for remarkable resilience. Regeneration failure was the exception, not the rule. Suppression of fire also had little impact on 21st-century fire or forests. Collectively, this research demonstrates that multiple streams of quantitative inquiry are necessary to better resolve how changing climate and disturbance will alter forests. Management steps could be taken to bolster vulnerable forests (e.g. reseeding after fires), if mechanisms of change are understood. However, forest-management strategies should not discount the inherent resilience of the system.

Download or read book Climate Changes and Wildfire Alter Vegetation of Yellowstone National Park But Forest Cover Persists written by Jason A. Clark and published by . This book was released on 2017 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present landscape simulation results contrasting effects of changing climates on forest vegetation and fire regimes in Yellowstone National Park, USA, by mid-21st century. We simulated potential changes to fire dynamics and forest characteristics under three future climate projections representing a range of potential future conditions using the FireBGCv2 model. Under the future climate scenarios with moderate warming (>2°C) and moderate increases in precipitation (3?5%), model simulations resulted in 1.2?4.2 times more burned area, decreases in forest cover (10?44%), and reductions in basal area (14?60%). In these same scenarios, lodgepole pine (Pinus contorta) decreased in basal area (18?41%), while Douglas-fir (Pseudotsuga menziesii) basal area increased (21?58%). Conversely, mild warming (

Download or read book Holocene Vegetation fire climate Linkages in Northern Yellowstone National Park USA written by Mariana A. Huerta and published by . This book was released on 2009 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Yellowstone National Park has been an important location for paleoecologic studies that focus on the use of charcoal data to reconstruct past fire activity and on the role of climate variations in shaping past vegetation and fire regimes. One hypothesis, which has been explored in other parts of the western U.S., is the idea that present-day summer-dry and summer-wet precipitation regimes were intensified during the early Holocene as a result of greater-than-present summer insolation and its effect on atmospheric circulation patterns. In Yellowstone, this hypothesis was previously examined at two sites, one in summer-wet and one in summer-dry precipitation regions. The records showed variation in both fire and vegetation history that supported the hypothesis. We present a fire and vegetation history from Blacktail Pond, located in Pseudotsuga parkland in the transitional region. The Blacktail Pond data indicate the following ecological history: prior to 12,000 cal yr BP, the site supported tundra vegetation and fire episodes were infrequent. Between 12,000 and 11,000 cal yr BP, Picea-Pinus parkland was established and fire activity increased; these changes are consistent with increasing temperature, as a result of rising summer insolation. From 11,000 to 7600 cal yr BP, the presence of a closed forest of Pinus and some Picea is attributed to high levels of winter moisture, but high fire activity indicates that summers were drier than at present. After 7600 cal yr BP, the presence of forest and steppe vegetation in combination with high fire activity suggest that middle-Holocene conditions were warm and dry. The decrease in Picea and Betula in the last 4000 cal yr indicates continued drying in the late Holocene, although fire-episode frequency was relatively high until 2000 cal yr BP. The pollen data at Blacktail Pond and other low-elevation sites in the northern Rocky Mountains suggest a widespread vegetation response in summer-wet regions to effectively wetter conditions in the early Holocene and decreased moisture in the middle and late Holocene. In contrast, the more-variable fire history among the three sites implies either that (1) summer moisture stress and fire conditions are related to year-round moisture balance and not well predicted by the hypothesis, (2) the transitional area between summer-wet and summer-dry precipitation regimes experienced complicated shifts in effective moisture through time, and/or (3) fire-episode data have a limited source area that makes it difficult to separate local influences from regional climate changes in understanding long-term variations in fire-episode frequency.

Download or read book Aboveground Net Primary Production and Leaf area Index in Early Postfire Vegetation in Yellowstone National Park written by Rebecca A. Reed and published by . This book was released on 1999 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aboveground net primary production (ANPP) and leaf-area index (LAI) of lodgepole pine (Pinus contorta var. latifolia Engelm. ex Wats.) saplings and aboveground productivity of herbaceous vegetation components were determined 9 years after the 1988 fires in Yellowstone National Park (YNP). Measurements were made in four sites representing a wide range of early postfire vegetation present in YNP, including high-density lodgepole pine, low-density lodgepole pine, and two nonforest stands. LAI of the pine saplings and total ANPP (trees plus herbs) generally increased with increasing sapling density, from 0.002 m2 m- 2 and 0.25 Mg ha- 1 year- 1 in the infertile nonforest stand (100 pine saplings ha- 1) to 1.8 m2 m- 2 and 4.01 Mg ha- 1 year- 1 in the high-density pine stand (62,800 saplings ha- 1). Aboveground herbaceous productivity was not strongly correlated with sapling density, but appeared to be influenced by soil fertility. In the high-density pine stand, tree ANPP and LAI were within the lower range of values reported for similar mature coniferous forests. This finding suggests that at least some ecosystem processes (related to ANPP and LAI) may have nearly recovered after only 9 years of postfire succession, in at least some of the young forests developing after the 1988 Yellowstone fires.

Download or read book Yellowstone Vegetation written by Don G. Despain and published by Roberts Rinehart Publishers. This book was released on 1990 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive view of vegetation types, distribution, and the natural forces that influence plant succession in Yellowstone.

Download or read book Recovery of Forest Resources from the Greater Yellowstone Wildfires Exxon Valdez Oilspill and the Mount St Helens Eruption written by United States. Congress. House. Committee on Agriculture. Subcommittee on Forests, Family Farms, and Energy and published by . This book was released on 1991 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Postfire Regeneration Dynamics in California s National Forests written by Kevin Robert Welch and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study examines postfire regeneration patterns in low to mid-elevation forests of northern and central California where conifers co-exist and compete with hardwoods and shrubs in the postfire environment. Due to fire suppression policies, timber harvest, and other management practices over the last century, many low- to mid-elevation forests in California have accumulated high fuel loads and dense, multi-layered canopies that are dominated by shade-tolerant and fire-sensitive conifers. These conditions promote high-intensity fires, which have major effects on forest structure, function, and composition. We established 1,854 survey plots in nineteen wildfires on ten National Forests across a range of elevations, forest types, and fire severities in central and northern California to provide insight into factors that promote natural tree regeneration after wildfires and the differences in post-fire responses of the most common conifer species and hardwood species. We developed a zero-inflated negative binomial mixed model with random effects to understand the importance of ten environmental variables in predicting conifer regeneration. This model identified as important factors distance to potential seed tree, annual precipitation, presence of regenerating shrubs, litter cover, fire severity and pre-existing forest type. We documented widespread conifer regeneration failure with nearly 50% of all plots devoid of conifer regeneration. When regeneration did occur, it was dominated by shade-tolerant but fire-sensitive firs, Douglas-fir and incense cedar. Active forest restoration (planting, brush control, reduction of undesirable species, etc.) may be necessary in more severely burned areas farther from seed trees where natural regeneration is insufficient to restore forest composition and structure, increasing forest resiliency in the face of climate change and augmented levels of fire disturbance. However, conifers do not exist in isolation in these forests and the interaction with other functional woody plant types must be considered. This study adds a unique contribution to understanding postfire regeneration dynamics by comparing the relative success of hardwoods to conifers across a fire severity gradient and in the first decade after mixed-severity fires. By utilizing vegetative sprouting (and to a lesser extent sexual reproduction), hardwood trees and shrubs are able to quickly capitalize on available resources and this ability may confer a competitive advantage to hardwoods. The results of this study indicate that increased fire severity leads to greater relative density of hardwoods via a combined impact of resprouts and seedlings, creating alternative states where hardwoods and shrubs (that suppress the relatively few conifer seedlings that do establish) may dominate for many years after disturbance. To a great extent, the future status of California's forests will depend on tree species' responses to patterns and trends in fire activity and behavior and post-fire management decisions.

Download or read book The Year Yellowstone Burned written by Jeff Henry and published by Rowman & Littlefield. This book was released on 2015-05-01 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Yellowstone fires of 1988 consumed nearly 800,000 acres—36 percent of the park. In the years following, spectacular wildflowers rose from the ashes and trees rapidly reclaimed the landscape. In this twenty-five-year look back at the fires, author and photographer Jeff Henry recalls not only the summer of 1988, when he witnessed and photographed nearly every aspect of the fires, but also the years since as nature healed the charred landscape. A beautiful book that depicts nature as simultaneously malevolent and beneficent, The Year Yellowstone Burned demonstrates the resilience of one of our continent’s most dynamic ecosystems.

Download or read book Scorched Earth written by Rocky Barker and published by Island Press. This book was released on 2013-09-24 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1988, forest fires raged in Yellowstone National Park, destroying more than a million acres. As the nation watched the land around Old Faithful burn, a longstanding conflict over fire management reached a fever pitch. Should the U.S. Park and Forest Services suppress fires immediately or allow some to run their natural course? When should firefighters be sent to battle the flames and at what cost? In Scorched Earth, Barker, an environmental reporter who was on the ground and in the smoke during the 1988 fires, shows us that many of today's arguments over fire and the nature of public land began to take shape soon after the Civil War. As Barker explains, how the government responded to early fires in Yellowstone and to private investors in the region led ultimately to the protection of 600 million acres of public lands in the United States. Barker uses his considerable narrative talents to bring to life a fascinating, but often neglected, piece of American history. Scorched Earth lays a new foundation for examining current fire and environmental policies in America and the world. Our story begins when the West was yet to be won, with a colorful cast of characters: a civil war general and his soldiers, America's first investment banker, railroad men, naturalists, and fire-fighters-all of whom left their mark on Yellowstone. As the truth behind the creation of America's first national park is revealed, we discover the remarkable role the U.S. Army played in protecting Yellowstone and shaping public lands in the West. And we see the developing efforts of conservation's great figures as they struggled to preserve our heritage. With vivid descriptions of the famous fires that have raged in Yellowstone, the heroes who have tried to protect it, and the strategies that evolved as a result, Barker draws us into the very heart of a debate over our attempts to control nature and people. This entertaining and timely book challenges the traditional views both of those who arrogantly seek full control of nature and those who naively believe we can leave it unaltered. And it demonstrates how much of our broader environmental history was shaped in the lands of Yellowstone.

Download or read book Regeneration of Montane Forests 24 Years After the 1988 Yellowstone Fires A Fire catalyzed Shift in Lower Treelines written by Daniel C. Donato and published by . This book was released on 2016 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forests near the lower limit of montane tree cover are expected to be particularly vulnerable to warming climate, potentially converting to non-forest for prolonged periods if affected by canopy-removing disturbances. Such disturbance-catalyzed shifts are by nature stochastic, offering few opportunities to test these predictions. We capitalized on a landmark event exemplary of recent large disturbances?the 1988 wildfires in Yellowstone National Park (USA)?to investigate long-term (24-yr) regeneration dynamics in Douglas-fir (Pseudotsuga menziesii var. glauca) forests, which compose the lower treeline yet have received little study. We tested the hypothesis that, under current conditions (warmest decades in last 6000 yr), dry lower-margin stands are less apt to attain self-replacement than adjacent, but more mesic, stands farther from the ecotone. Mesic sites characterized by dense forests prefire regenerated robustly regardless of burn severity, even in large high-severity patches, whereas dry sites did so only if nearby seed sources survived (i.e., small patch size or moderate burn severity). Regeneration continued over two decades, peaking between ~5 and 15 yr, with mesic stands continuing regenerating beyond 15 yr to a greater degree than dry stands. Self-replacement of stands by 24 yr postfire was nearly universal in mesic stands, variable but common in dry stands not adjacent to the lower ecotone, and uncommon in dry stands near the ecotone?particularly if burned at high severity. Whether the lack of regeneration in ecotonal stands is categorically directional with warming climate or part of a long-term cycle is unresolved, but we estimate that the 1988 fires converted > 4000 ha of lower-montane forest to grass/sage steppe for at least several decades, possibly indefinitely given current trends in climate. These data support the notion that climate-driven shifts in vegetation cover are likely to occur in punctuated fashion with disturbances, with relatively abrupt implications for montane forest cover, biogeography, and ecosystem function.